Computer-based software applications are often monitored during execution to identify undesirable performance characteristics such as bottlenecks and infinite loops. For example, a software application developed in accordance with the Java™ 2 Platform, Enterprise Edition, may be “instrumented” with software probes in one or more locations throughout source code and/or bytecode, including in classes such as system classes, to allow performance monitors to gather such information during its execution. Unfortunately, instrumentation can sometimes interfere with an application or its operating environment, such as where instrumentation of Java™ Virtual Machine (JVM) system classes changes the order in which the system classes are normally loaded, resulting in JVM failure. Thus, for example, whereas the java.util.HashMap system class is normally loaded after the java.lang.String system class, if instrumentation code inserted into java.lang.String directly or indirectly references java.util.HashMap, the JVM will attempt to load java.util.HashMap first, causing the JVM to crash in many situations depending on the JVM implementation. It would therefore be advantageous if computer-based Java™ application software could be instrumented without causing changes in class loading order that would lead to such failures.